The invention relates to a spinning machine having several spinning stations for spinning yarns from slivers which are fed to the spinning stations in cans, guiding devices for the slivers being provided between the cans and the spinning stations.
The feeding of the fiber material, that is to be spun, in the form of slivers situated in cans, is known, for example, in the case of open-end spinning machines. In the case of the machines that are on the market, the slivers are withdrawn directly by the sliver feeding device of the individual spinning stations from the cans which stand in front of and partially under the spinning arrangement.
It is also known (German Patent Document DE-C 23 35 740) to arrange the cans on a platform above the spinning machine in the case of open-end spinning machines and to feed the slivers to the spinning stations through guiding tubes. These guiding tubes, which are provided with baffles, are to serve as an intermediate storage device which, because of a special construction, is fed by a continuously running feeding device nevertheless intermittently. The sliver is then, essentially without tensile stress, to be guided through the respective guiding tube.
The feeding of fiber material in the form of slivers made available in cans is known also in the case of other fast-running spinning machines, such as in the case of wind-around spinning machine or air spinning machines. As a rule, these are one-sided machines where the slivers are fed to the spinning stations from above and are removed from the cans deposited on the rear of the spinning machine. In this case, guiding devices for the slivers are provided in the form of rollers and guide rods.
It is also known (German Patent Document DE-PS 817 572) to feed slivers in cans in the case of ring spinning machines, in which case, the cans are deposited on platforms or in a space above the spinning machine. This results in relatively long travelling paths with one or several vertical sections which carry the risk that the slivers may hang out, that is, are drawn or drafted uncontrollably because of their own weight. Such an arrangement is therefore possible only for slivers which have a relative coarse size and therefore have a relatively high strength.
However, the spinning of coarse-size slivers is very difficult on ring spinning machines. Since the ring spinning machines have only a relatively slow delivery speed on the outlet of the drafting units, the feeding rollers of the drafting units--taking into account the required drafting--must run very slowly, that is, at rotational speeds of one revolution per minute or less. Technically, it is extremely difficult to let long shafts, like the feeding rollers of drafting units, run with sufficient precision at such low rotational speeds. There is the risk that these shafts may only turn jerkily so that no controlled drafting is obtained. The feeding of the fiber material that is to be spun in cans has therefore in practice not been carried out successfully in the case of ring spinning machines.
In an older German Patent Application (P 40 41 112.5, PA 1170, P 9342, which is no prior publication, (corresponding U.S. patent application Ser. No. 07/809,141, filed Dec. 18, 1991 now abandoned and subsequent continuation-in-part application Ser. No. 07/948,638, filed Sep. 23, 1992) it is suggested to provide a conveyor belt for the guiding devices. In this case, a separate conveyor belt is assigned to each sliver, against which a sliding skid or a second belt may possibly place itself.
It is an object of the invention to develop a spinning machine of the initially mentioned type such that also fine slivers may be fed in the cans without the risk of faulty drafting, in which case the manufacturing expenditures should be kept low.
This object is achieved according to preferred embodiments of the invention in that the guiding devices comprise a conveyor belt for at least two slivers which are to be conveyed side-by-side.
In the development according to the invention, it is achieved that the slivers are supported and are nevertheless moved in the transport direction. As a result, it is possible to feed also relatively thin slivers in cans, that is, slivers of sizes of approximately Nm 0.4 to 0.8. In this case, these fine slivers may also be conveyed in the vertical direction along larger sections. It is therefore possible to carry out a can feeding also in the case of ring spinning machines since, because of the fine-sized slivers, while taking into account the drafting, the feeding roller pairs of the drafting units still rotate at a sufficiently high speed so that a uniform round rotating is ensured. By means of this can feeding, it will then be possible in the case of ring spinning machines to do without a machine, specifically the flyer, connected in front of it. In the case of other spinning machines, which are provided with drafting units into which slivers enter, it is possible to feed finer slivers so that the drafting units can then be simplified. For example, in the case of such machines, there exists the possibility of using, instead of five-cylinder drafting units, the three-cylinder drafting units which today are customary in the case of ring spinning machines.
The feeding of finer slivers also has advantages in the case of open-end machines because then the opening work for the separating of the fibers is less so that the fibers are processed more carefully during the opening-up. It is therefore possible to spin finer yarns with less damaged fibers so that the yarns have a higher quality.
As a result of the fact that several slivers are assigned to one conveyor belt, the manufacturing expenditures are reduced because one conveyor belt can transport the slivers of several spinning stations. In this case, it may be provided that two slivers to be transported side-by-side are assigned to different sides of the machine. As an alternative or addition, it may, however also be provided that the two slivers, which are to be conveyed side-by-side, are assigned to the same side of the machine.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.